Rosuvastatin is one of HMG-CoA reductase inhibitors, administered as its calcium salt. HMG-CoA reductase inhibitors (also called statins) are optically active molecules containing chiral (3R,5S)-hept-6-enoic or -heptanoic acid moiety. They are used for manufacturing medicaments to treat hypercholesterolemia. HMG-CoA reductase inhibitors are also simvastatin, pravastatin, lovastatin, atorvastatin and fluvastatin. Their pharmaceutical activity may be related to their structure where said chiral hepanoic or heptenoic acid (or a salt, ester or lactone) is bound to a core (denoted Het), which may be a heterocycle, such as substituted pyridine, pyrimidine, pyrrole.
Several methods were developed to introduce chirality into molecules, such as for example using optically active 3-silyloxyglutaric acid monoalkyl esters (WO 03/087112), 1-cyano-2(S)-[(t-butyldimethylsilyl)oxy]-4-oxo-5-triphenylphosphoranylidene-pentane (WO 2004/052867) or 3(S)-hydroxy-γ-butyrolactone (EP 521471). These reagents are rather complex so there is a need for simpler i.e. cheaper chiral sources.